Buoyant body of plastic provided with a tubular passage therethrough



l 'I Jan' 2 8 .1969 I K. EQER-QLSEN ETAL I 3,423.7

BuoYANT Bom oF PLASTIC PRQVIDED WITH A' TUBULAR PASSAGE THERETHROUGH`Filed May 16.k 1966 v Sheet l of 2 Jan. 2s, 1969 K. BEYERPOLSEN ETAL 3,23,776 BUYANT BODY OF` PLASTIC PROVIDEDl WITH A TUBULAR PASSAGETHERETHROUGH Filed May 16, 1966 VSheet'of 2 FIGA United States Patent O160,650 U.s. C1. 9 8 Int. ci. Bash 21/52 4 Claims ABSTRACT F THEDISCLOSURE A buoyant plastic body has a tubular element extendingthrough said buoyant body forming a diametrical tubular passagetherethrough. The tubular element has an extension protrudingexteriorily from the body as a tubular stub. A plurality ofsubstantially radially extending circumferentially spaced rib elemntsare secured to the exterior surface of the stub and to the adjacentoutside wall of the tubular body. These ri'b elements are molded to thestub and also to the buoyant body exterior wall. A clamp device may beprovided upon the stub and the buoyant body, tubular element and ribsmay be molded from the same plastic material and are of the samethickness as the walls of the -body and the tubular element.

The present invention relates to a buoyant body of plastic furnishedwith a tubular passage therethrough particularily, but notrestrictively, a hollow buoyant body referred to as a rod buoy, becausea mooring or marking rod is threaded through and positioned in thetubular passage.

In the following the invention shall be described in connection with rodbuoys, but it shall be understood that the invention can be practisedwith all kind of buoyant bodies having through-going openings, such asshing gear, floats, fenders, etc.

Rod buoys made from a plastic material have in recent years come intoextensive use, in particular for fishing gear and for mooring purposes.Such buoys are provided with a through-going passage by means of atubular element which is sealingly molded to the body wall. The rodpositioned through the passage may have an upper free standing portionwhich is provided with a fastening eye for a rope or the like orprovided with a marking device, for instance a flag, making the buoymore easily to spot when iloating in the seat, the lower portion of therod being positioned below the sea surface being provided with Y aweight in order to keep the rod and the buoy in upright position whenfloating in the sea. In order to fasten the rod to an inateable hollowbody, i.e, to prevent that the rod is sliding in the passage, thetubular element can be made from a flexible material having in resultthat the tubular element, when the buoyant body is inflated, due to theair pressure will be pressed rmly against the rod and thereby lock sameto the hollow body. Such a rod buoy is described in Norwegian Patent No.90,515. The rod can, however, be fastened to the buoy otherwise, mostsimply by positioning a thickening on the rod adjacent each mouthopening, thus preventing the rod from sliding in the passage.

Rod buoys which shall be used as mooring buoys,

3,423,776 Patented Jan. 28, 1969 fenders and the like, are frequentlyprovided with a throughgoing steel rod which at the passage mouths oneach side of the buoy is furnished with disc-like Stoppers restingfirmly against the outside of the float proper. See for instance U.S.Patent No. 2,381,394.

Regardless ofwhich purpose the buoy shall serve or how the rod is beingfastened to the buoy, there will between the rod and the -oat proper beprevailent various kinds of stresses in the form of tensions, bendingandtorsional stresses because the rod will be anchored to some object orother, while the floating buoyant body constantly is subjected to forcesfrom the sea in the shape of waves, streams and the like.

These stresses .will concentrate themselves in the region between thejoint between the tubular element and the buoy wall, and sooner or latera fatigue failure may occur in the plastic material in the said region.In order to avoid this it therefore has been customary to provide thetubular element and/or the body with reinforcements by means ofincreasing the thickness of the material` but this means has not provedto be a satisfactory solution, among other reasons because during themolding operation of the buoyant body it is a diilicult task to achievethe proper throughgoing curing of the material, particularily when thebody is provided with local thickenings. A special curing step of theseparts, for instance by applying more heat to same, very easily will leadto an over-curing of the adjacent thinner parts of the `body having as aresult that these `will be weakened, a fact which makes it more feasibleto cure such thicker parts somewhat less than ideal, but thereby thesethicker parts will of course not be as strong as intended. Furthermoresuch thicker material parts of the oat will demand longer productiontime, lessen the reproducability and also result in a heavier and moreexpensive product. Applicants U.S. Patent No. 3,081,493 illustratesexamples of such reinforcements.

The chief object of the invention is to overcome the above describeddifliculties and the draw-backs in connection with known buoyant bodiesof this type and this is in accordance with the invention accomplishedin that said tubular element has an extension in the shape of a freestanding tubular stub protruding out from the wall of the buoyant body,a plurality of substantially radially extending circumferentially spacedrib elements being molded to the cylindrical outside surface of the stuband to the bordering outside wall of the buoyant body.

The rib elements on the buoyant body in accordance with the inventionact as a combination of reinforcing ribs and a spring means, since theribs will flexibly resist relative movements between the rod yand thebuoy, when tension, bending or torsional stresses or a combination ofsuch are acting between the rod and the buoyant body so that neitherwear nor fatigue failures will occur in the plastic material in thebuoy.

Furthermore a hollow body or float in accordance with the invention canbe made having substantially uniform goods thicknesses, a fact which toa large degree facilitates the molding and the correct curing of theplastic material, a reproducible production and also result in a productrelatively lightweighted.

For a complete understanding of the invention, reference shall be madeto the detailed description which follows and to the accompanyingdrawings, in which:

FIGURE 1 is a side view of a rod buoy in accordance with the invention;

FIGURE 2 is on a larger scale a fragmentary sectional view of the lowermouth section of the buoy shown in FIGURE 1;

FIGURE 3 is aside view on a larger scale of the upper part of the buoyshown in FIGURE 1;

FIGURE 4 is a sectional view through the mouth portion of a modifiedembodiment of a buoy in accordance with the invention, said sectiontaken along the plane IV-IV shown in FIGURE 5, 'and FIGURE 5 is a planview of half of the object shown in FIGURE 4.

FIGURE 1 shows a side view of a buoy 2 in accordance with the invention.The buoy is of ovoid shape provided with a throughgoing passage by meansof a tubular element 4 molded integral with the body proper in a per seknown fashion. As appearing best from the fragmentary view shown inFIGURE 2, the tubular element 4 is molded to the buoy wall 6 at thejunction 8. The tubular element has an extension protruding out from theoutside surface of the body wall in the shape of a stub 10, and in thetransition zone between the buoy wall and the tubular element areprovided a number of circumferentially spaced rib-like elements 12-12,each of which is molded to the buoy wall as well as to the tubularelement, along edges 14 and 16 respectively, so that each rib 12 has anoutwardly pointing free edge 18. In the shown embodiment of theinvention each rib ends a small distance short of the extremity of thepipe stub there is provided a round cylindrical stub 20 for the supportof a clamp 22 which by means of a screw 24 can be clamped onto a rod orthe like 26 which beforehand is threaded through the passage. Aspreviously mentioned the rod can be attached to the buoy also by makingthe tubular element 4 from a relatively soft or flexible material whichby inflating the buoy will be pressed against the rod.

The number of the ribs and their configuration is not particularlycritical, but it constitutes a feature of the invention that the ribthickness shall not deviate `substantially from the thickness of thewall in the buoy and the tubular element.

The ribs at the other mouth opening 30 of the buoy are, as is best shownin FIGURE 3, somewhat differently shaped since the buoy here ends with asubstantially plane end surface 32, so that the ribs 34 have a likewisesub stantialy straight joint to the buoy as well as to the tubularelement.

FIGURES 4 and 5 show a different embodiment of the invention, whereinthe buoy wall 40 in the region 44 about the mouth opening 42 is curvedinwardly towards the center of the buoy, the free standing edge 52 ofeach rib 56 joining the body wall in a tangential relationship at 54.

The ribs 56 are here shown as extending in a straight radial plane, butit shall be understood that it is within the scope of the invention todesign the ribs s0 that they curve radially outwards such as indicatedwith dotted lines 57 in FIGURE 5. The embodiment of the invention asshown in FIGURES 4 and 5 is primarily designed to be used for mooringbuoys and the like, the free edges 52 of the ribs 56, and the angularmouth edge of the tubular element 50 is positioned in a common planestanding perpendicular to the axis of the tubular passage.

It will be understood that there is no hindrance to giving the mouthregion on a buoy in accordance with the invention a shape different fromthe embodiment shown in FIGURES 2, 3 or 4, for instance in the shape ofa combination of features from the embodiment shown in FIGURES 3 and 4respectively, so that the ribs extend outwardly as well as inwardlyrelative to the outside surface of the buoy.

A buoy devised in accordance with the invention will be strengthened inaspect of various 'forms of stresses or combinations thereof.

Usually the rod will be fixed to the buoyant body so that it cannot turnrelative to same, for instance by means of a clamp device as shown.Between the rod and body there will be present more or less continuoustorsional and axial stresses, which, however, are initially received bythe rib elements, and thereafter transferred and distributed across arelatively large surface area of the buoy. In the embodiment shown inFIGURE l most of the forces between the buoy and the rod will naturallybe transferred via the clamp device 22, although practice has shown thatafter a short period of use in the open sea, the rod will adhere to thetubular passage wall all along the passage due to accumulation of salt,dirt, etc.

As will be understood axial forces acting between the buoyant body andthe rod likewise will be received by the rib elements and effectivelytransferred and distributed across the buoy wall.

A correct transfer and distribution of forces and stresses between therod and buoy are enhanced when the goods thicknesses of the buoy wall,the tubular element and the ribs are made about the same. This meansthat all goods subject to stresses are stressed or able to undergoelastical deformation of the same order, i.e. stress concentrations areavoided.

The fact that all parts in a buoyant body in accordance with theinvention have about the same goods thicknesses means furthermore thatthe entire buoyant body shall be subjected to the same curing treatment.This circumstance to a large degree facilitates a reproducable andfaultless production.

We claim:

1. An ovoid plastic buoy having walls comprising a buoyant body offlexible plastic material, a tubular element formed integral with thebody walls of Said buoyant body forming a tubular passage through saidbody from one point on the outside surface to a diametrically opposedsecond point on the outside surface, said element having an extensionprotruding out from the wall of said buoyant body in the shape of a freestanding tubular stub and a plurality of substantially radiallyextending circumferentially spaced elongated rib elemnts molded to theoutside surface of said stub and to the adjacent outside wall of saidbuoyant body, said rib elements, tubular elem-ent and body Walls beingof the same material and thickness throughout to promote uniform curingand strength there to; and an integrally molded unobstructed hub portionon said stub adjacent the rib elements, and clamp means thereon fordeformably initially clamping the tubular element to a rod elementinserted therein for association with said buoyant body such as thestaff of a marker flag.

2. An ovoid plastic buoy having an upper pole of major amplitudesurmounting a lower pole of minor amplitude when in the normal operatinguse, comprising in combination:

(a) an airtight inflatable hollow body including walls of non-rigid,plastic material and being symmetrical about a vertical central axis;

(b) a tubular sleeve element formed of relatively flexible plasticintegral with said walls and body and disposed on the vertical axis toform an open tubular passage completely through said body from pole topole,

(c) said tubular element having at least one end pro jecting from an endin the form of a free standing tubular stub;

(d) a plurality of elongated, substantially radially extendingcircumferentially spaced exterior rib elements integrally molded to thesurface of said stub and to the adjacent outside wall of said body; saidribs, tubular element and body being substantially of the same 6material and thickness throughout to promote uni- References Cited formcuring and added streng-th thereto of said plas- UNITED STATES PATENTS cbufyiand 322,088 7/1885 Behrens 4;*4491 (e) an lntegrally molded hubportlon on sald tubular 3,081,493 3/1963 Beyer o1sen et al. 264 278 stubadjacent said ribs and clamp means thereon for 5 3,144,729 8/1954Jonassen 4344.91 X deforming the tubular element and clamping a rod50,581 10/ 1865 Henis 73-319 element as of a marker flag insertablethrough said 2,163,795 6/ 1939 Merralls 9-8 tubular element forassociation with said buoy. 2,358,472 9/ 1944 Owens 73-3 22.5 3, A buoyas dened in claim 2 wherein said tubular 10 gscln element projectsbeyond the body at both poles to form two stubs, and said rib elementsare integrally molded to 3262089 7/1966 Proctor et al 9`8 X andinterconnecting the outer surface of each stub and Y FOREIGN PATENTSsaid body adjacent each pole; and the rib elements formed 580,177 7/1959 Canada. at the lower pole having the said hub portion molded 15581,601 10/ 1946 Great Britain. adjacent thereto.

4. A buoy as dened in claim 3 wherein the lower pole TRYGVE B' BLIXPrlmary Exammer' rib elements are substantially longer than those at theUS Cl- XR upper pole. 43-25, 44.9

